(A) Require new construction or substantial improvements of residential structures to have the lowest floor, including basement, elevated to or above 1 foot above the base flood elevation.
(B) Require new construction or substantial improvements of nonresidential structures to have the lowest floor, including basement, elevated to or above 1 foot above the base flood elevation or, together with attendant utility and sanitary facilities, to be floodproofed so that below that level the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. A registered professional engineer or architect shall certify that the standards of this division are satisfied. Such certification shall be provided to the Code Enforcement Official as set forth in § 153.14(B)(7).
(C) Appurtenant structures used exclusively for storage of motor vehicles, and storage of other items readily removable in the event of a flood warning may have their lowest floor below 1 foot above the base flood elevation provided the structure is capable of withstanding hydrostatic and hydrodynamic forces caused by the base flood and provided that no utilities are installed in the structure except elevated or flood proofed electrical fixtures. If the structure is converted to another use, it must be brought into full compliance with the minimum standards governing such use.
(D) Require for all new construction and substantial improvements that fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria: A minimum of 2 openings having a total net area of not less than 1 square inch for every square foot of enclosed area subject to flooding shall be provided. The bottom of all openings shall be not higher than 1 foot above grade. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(E) Elevated structures. All new construction or substantial improvements of an existing structure that includes a fully enclosed area located below the lowest floor formed by the foundation and other exterior walls shall be designed to be an unfinished or flood resistant enclosure. The enclosure shall be designed to equalize hydrostatic flood forces on exterior walls by allowing for the automatic entry and exit of floodwater.
(1) Designs for complying with this requirement must be certified by a professional engineer or meet the following minimum criteria:
(a) Provide a minimum of 2 openings with a total net area of not less than 1 square inch for every square foot of enclosed area subject to flooding;
(b) The bottom of all openings shall be no higher than 1 foot above the higher of the exterior or interior grade or floor immediately below the opening;
(c) Openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic flow of floodwater in both directions without manual intervention.
For crawlspace foundation types, construction must follow the guidelines contained in FEMA TB 11-01, Crawlspace Construction for Structures Located in Special Flood Hazard Areas: National Flood Insurance Program Interim Guidance;
(d) Below grade crawlspaces are prohibited at sites where the velocity of floodwaters exceed 5 ft/second;
(e) Interior grade of the crawlspace below the BFE must not be more than 2 feet below the lowest adjacent exterior grade (LAG);
(f) Height of the below grade crawlspace, measured from the lowest interior grade of the crawlspace to the bottom of the floor joist must not exceed 4 feet at any point;
(g) Contain an adequate drainage system that removes floodwaters from the interior of the crawlspace.
(F) Within AH zones adequate drainage paths around structures on slopes shall be required in order to guide floodwaters around and away from proposed structures.
(G) Manufactured homes.
(1) All manufactured homes shall be anchored to resist floatation, collapse, or lateral movement. Manufactured homes must be anchored in accordance with local building codes or FEMA guidelines. In the event that over-the-top frame ties to ground anchors are used, the following specific requirements (or their equivalent) shall be met:
(a) Over-the-top ties be provided at each of the four corners of the manufactured home, with two additional ties per side at intermediate locations and manufactured homes less than 50 feet long requiring 1 additional tie per side;
(b) Frame ties be provided at each corner of the home with 5 additional ties per side at intermediate points and manufactured homes less than 50 feet long requiring 4 additional ties per side;
(c) All components of the anchoring system be capable of carrying a force of 4,800 pounds; and
(d) Any additions to the manufactured home be similarly anchored.
(2) Require that all manufactured homes to be placed or substantially improved within special flood hazard areas on the community's FIRM on sites:
(a) Outside of a manufactured home park or subdivision;
(b) In a new manufactured home park or subdivision;
(c) In an expansion to an existing manufactured home park or subdivision; or
(d) In an existing manufactured home park or subdivision on which a manufactured home has incurred substantial damage as the result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above 1 foot above the base flood elevation; and be securely anchored to an adequately anchored foundation system in accordance with the provisions of division (G)(1) above.
(3) Require that manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision within special flood hazard areas on the community's FIRM that are not subject to the provisions of division (G)(2) above be elevated so that either:
(a) The lowest floor of the manufactured home is at or above 1 foot above the base flood elevation; or
(b) The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade; and be securely anchored to an adequately anchored foundation system in accordance with the provisions of division (G)(1) above.
(H) Recreational vehicles placed on sites within the special flood hazard areas on the community's official map shall either:
(1) Be on the site for fewer than 180 consecutive days;
(2) Be fully licensed and ready for highway use; or
(3) Meet the permit requirements and the elevation and anchoring requirements for manufactured homes of this chapter. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect type utilities and security devices, and has no permanently attached additions.
(I) Located within the areas of special flood hazard established in § 153.04 are areas designated as AO Zones. These areas have special flood hazards associated with base flood depths of 1 to 3 feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and indeterminate; therefore, the following provisions apply within AO Zones:
(1) All new construction and substantial improvements of residential structures shall have the lowest floor (including basement) elevated above the highest adjacent grade at least as high as 1 foot above the depth number specified in feet on the community's FIRM (at least 2 feet if no depth number is specified); or
(2) All new construction and substantial improvements of nonresidential structures shall:
(a) Have the lowest floor elevated above the highest adjacent grade at least as high as 1 foot above the depth number specified in feet on the community's FIRM (at least 2 feet if no depth number is specified); or
(b) Together with attendant utility and sanitary facilities be completely floodproofed to or above that level so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. Such certification shall be provided to the official as set forth in § 153.14(B)(7).
(3) Adequate drainage paths around structures on slopes shall be required in order to guide floodwaters around and away from proposed structures.
(Ord. 3779, 11-3-2009; Am. Ord. 3934, § 1, 5-17-2016)
Penalty, see § 153.99